Determination of the loading path for tube hydroforming process of a copper joint using a fuzzy controller

摘要

Tube hydroforming of thin-walled parts ratio of the thickness to the diameter is too low and mainly depends on the process control parameters (the internal pressure and the axial feeding). These parameters determine the occurrence of forming limits, such as wrinkling and bursting. Trial-and-error method is not a convenient method to find loading path since it is costly. Convectional loading paths, which may easily result in a product with defects, cannot be used in this case. In this study, the loading path for hydroforming process of copper joint is determined using a fuzzy controller. The final goal is to obtain a calibrated product without any wrinkling or tearing. It is shown that the wrinkling, except severe wrinkling, is a repairable defect, while bursting is an irreparable defect. Simulation of the process is done by using finite element method in combination with a designed fuzzy controller. The Abaqus scripting interface is used for modeling the part and communicating with the Abaqus kernel. The explicit method is utilized to overcome convergence problems encountered in the implicit method.